Entity Framework多对多关系

1.模型类

    /// <summary>
    /// 角色类
    /// </summary>
    [Table("RoleTB")]
    public class RoleTB 
    {
        [Key]
        public int ID{get;set;}
        public string Name { get; set; }
        public string Desc { get; set; }
        public int Status { get; set; }
        [NotMapped]
        public virtual List<MenuTB> MenuTBs { get; set; }
        [NotMapped]
        public virtual List<UserTB> UserTBs { get; set; }
    }

    /// <summary>
    /// 用户
    /// </summary>
    [Table("UserTB")]
    public class UserTB 
    {
        [Key]
        public int ID { get; set; }
        public string UserName { get; set; }
        public string Password { get; set; }
        public string HeadImage { get; set; }
        [NotMapped]
        public virtual List<RoleTB> RoleTBs { get; set; }
    }

    /// <summary>
    /// 角色和用户中间表
    /// </summary>
    [Table("RoleUserTR")]
    public class RoleUserTR
    {
        [Key]
        [Column(Order = 0)]
        [ForeignKey("RoleTB")]
        public int RoleID { get; set; }
        public virtual RoleTB RoleTB { get; set; }
        [Key]
        [Column(Order = 1)]
        [ForeignKey("UserTB")]
        public int UserID { get; set; }
        public virtual UserTB UserTB { get; set; }

    }

2.测试代码

            using(var dbContext=new EntityDbContext())
            {
                RoleTB role = new RoleTB { 
                    Name="总管理员"
                };
                UserTB user1 = new UserTB { UserName = "admin", Password = "123456" };
                UserTB user2 = new UserTB { UserName = "liandy", Password = "123456" };
                dbContext.RoleTBs.Add(role);
                dbContext.UserTBs.Add(user1);
                dbContext.UserTBs.Add(user2);
                dbContext.SaveChanges();

                RoleUserTR roleUserTR1 = new RoleUserTR {
                    RoleID = role.ID,
                    UserID=user1.ID
                };
                RoleUserTR roleUserTR2 = new RoleUserTR
                {
                    RoleID = role.ID,
                    UserID = user2.ID
                };
                dbContext.RoleUserTRs.Add(roleUserTR1);
                dbContext.RoleUserTRs.Add(roleUserTR2);
                dbContext.SaveChanges();
            }

            using (var dbContext = new EntityDbContext())
            {
                UserTB user = dbContext.UserTBs.Where(u => u.UserName == "liandy").FirstOrDefault();
                dbContext.UserTBs.Remove(user);
                dbContext.SaveChanges();
            } 

            using (var dbContext = new EntityDbContext())
            {
                RoleTB role = dbContext.RoleTBs.Where(u => u.ID == 1).FirstOrDefault();
                List<UserTB> userTBs = dbContext.RoleUserTRs.Where(u => u.RoleID == role.ID).Select(u => u.UserTB).ToList();
            } 

3.验证数据库

    /// <summary>    /// 角色类    /// </summary>    [Table("RoleTB")]    public class RoleTB     {        [Key]        public int ID{get;set;}        public string Name { get; set; }        public string Desc { get; set; }        public int Status { get; set; }        [NotMapped]        public virtual List<MenuTB> MenuTBs { get; set; }        [NotMapped]        public virtual List<UserTB> UserTBs { get; set; }    }